The volcanic eruption of Mt. Unzen-Fugen which began in 1990, has ceased in 1995 but many dwellers in Shimabara city and Fukae town are still conflicting with many difficulties by change of human environmental system. Our continuous study through volcanic eruption revealed following points.1) Populations of disastrous area had rapidly decreased by refuge of dwellers for avoiding acute eruption. While this trend still continues in Shimabara city even after the end of active volcanic eruption, the population in Fukae has recovered by social increase. The industrial transition from primary sector (agriculture) to tertiary may act some role for such population movement.2) According with decline of eruption, irritant symptoms in eyes and throat have rapidly became to be less frequent., but those in respiratory system have slowly decreased. Chronic effects on respiratory system should be continuously examined.3) By analysis on relationship with asthma and domestic environment among school children, changes of family member by volcanic eruption seemed to affect significantly the prevalence of asthma attack.4) Follow up studies revealed that mental health condition of past-refugees has been still stressful even though the volcanic disaster has ceased. Administration on mental health care should be necessary for preventing Post Traumatic Disorders. As a conclusion, the re-organization and/or re-construction of local communities might be necessary for keeping high level of quality of life among dwellers who met disastrous natural hazards for long period.